Reciprocal door latch for laundry washing machine



Nov. 25, 1969 K. H. WOLVERTON RECIPROCAL DOOR LATCH FOR LAUNDRY WASHINGMACHINE Filed July 21, 1967 2 I 3 n :1 L' l J FIG 3 INVENTOR KEN/V577!ff h/oz Venn/u ATTORNEYS United States Patent 3,480,315 RECIPROCAL DOORLATCH FOR LAUNDRY WASHING MACHINE Kenneth H. Wolverton, Moline, Ill.,assignor to Ametek, Inc., New York, N.Y., a corporation of DelawareFiled July 21, 1967, Ser. No. 655,205 Int. Cl. Ec 1/04; D06f 39/14 US.Cl. 292175 5 Claims ABSTRACT OF THE DISCLOSURE The present inventionrelates to a reciprocable door latch for the inner cylindrical drum of alaundry washing machine, and more particularly to such a door latchwhich will automatically be locked in the event the inner drum begins torotate when the latch has been left in the open position.

A conventional form of laundry washing machine comprises an outercylindrical shell in which is rotatably mounted a cylindrical drum. Theouter shell is provided with a door or other access through which thearticles to be washed are introduced into a door formed in the wall ofthe inner shell. After the articles have been placed in the inner drum,the door is locked by a suitable latching mechanism which must bedependable so as to maintain the door locked throughout the rotary movement of the drum. Various forms of latching assemblies have beenproposed for this purpose. However, on occasion, the latches have beenleft unlocked and operation of the laundry machine commenced by rotatingthe inner drum. Under these conditions, the door was open and thelaundry machine damaged, with possible loss or destruction of thearticles being washed. While several forms of electrical safety circuitsand interlocks have been devised, these have not been successful sinceextensive modifications of the laundry machines were required for theirinstallations. Further, the complexity of these safety arrangementsadded unduly to the cost of the laundry machines.

It is therefore an object of the present invention to provide a noveland improved reciprocable door latch.

Another object of the invention is to provide a reciprocable door latchparticularly adapted for the inner rotatable drum of a laundry washingmachine.

A further object of the invention is to provide a latch assembly for thedoor of the inner drum of a laundry machine which will automaticallymove to the locking position on rotation of the inner drum.

In one aspect of the invention, there may be provided a bracket having abore therethrough and mounted upon the outer surface of the inner drumdoor adjacent to the door edge. A keeper element is mounted on the drumso as to lockingly cooperate with the latch. A guide sleeve is attachedto the bracket and is coaxial with the bracket bore. A latch bolt havinga forward end and an outer end is slidably mounted in the bracket andguide sleeve and is urged outwardly into the locking position by aspring mounted within the guide sleeve. A handle is mounted on the outerend of the latch bolt 3,480,315 Patented Nov. 25, 1969 "ice for freepivotal movement in a plane perpendicular to the reciprocable movementof the latch bolt. Extending outwardly from the guide sleeve away fromthe bracket is a longitudinal plate having an arcuate cross section. Thelongitudinal edges of this plate guide the movement of the handle whenthe handle is pivoted to a position substantially parallel to the doorsurface so that the latch bolt is movable to the locking position. Onthe outer end of the longitudinal plate there is formed a shallow notchwhich can releasably receive the handle when the handle is pivoted to aposition perpendicular to the door surface after the latch bolt has beenmoved to its unlocked position. In the unlocked position, the handleextends radially outwardly into the path of projecting structure on theouter drum so as to be pivoted from this position when the inner drumbegins to rotate. When the handle is released from this unlockedposition, the latch bolt will be moved to the locking position under theaction of the spring in the guide sleeve.

Other objects, features and advantages of the invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings which are exemplary.

In the drawings:

FIG. 1 is a partial transverse sectional view of the laundry washingmachine incorporating the present invention;

FIG. 2 is an enlarged top plan view of the latch bolt according to theinvention in the locking position and taken along line 22 of FIG. 1;

FIG. 3 is a front elevational view of the latch bolt of FIG. 2, showingthe bolt and handle in the unlocked position;

FIG. 4 is an end view of the latch illustrated in FIG. 3; and

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 3.

Referring to the drawings wherein like reference symbols indicate thesame parts throughout the various views, a specific embodiment of theinvention will be described in detail.

As may be seen in FIG. 1, the stationary outer shell or drum of aconventional side loading washing machine is indicated at 10 and isprovided with the usual door .11 which is closed in regular use of themachine and which may be of the sliding type or of the swinging hingetype. An inner drum 12 is rotatably mounted within the shell 10 withboth the shell and the drum being of the cylindrical type. The innerdrum 12 is also provided with a door 13 which may be of the sliding orhinge type. The inner door 13 is provided with a latch bolt assemblygenerally indicated at 14 which is essential since the inner door mustbe positively locked during the operation of the machine.

Such a latching arrangement for the outer door may be 7 optional. 7

Referring to FIGS. 2 to 5, the latch assembly 14 comprises a latch boltassembly indicated generally at 15 and a keeper 16. The keeper is in theform of a bracket having a bore 17 therein and is mounted on the outersurface of the inner drum 12 adjacent the door opening. The latch boltassembly comprises a bracket 18 having a bore 19 therein, the bracketbeing mounted on the outer surface of the inner door 13 for cooperationwith keeper 16. A cylindrical guide sleeve 20 is attached to bracket 18and has a bore 21 which is coaxial with the bore 19. A latch bolt 22 isslidably mounted in the guide sleeve 20 and bracket 18, and has aforward end 23 and an outer end 24. The for-ward end 23 may be slightlytapered and has a notch 25 therein. There is an annular shoulder 26 onthe latch bolt 22 and a spring 27 seated against this shoulder andagainst a retaining member 28 mounted on the outer end of the guidesleeve 20.

On the outer end 24 of the latch bolt, there is mounted a handle 29which is freely pivotable in a plane perpendicular to the direction ofreciprocable movement of the latch bolt. The handle 29 is retained inposition by a nut 30 and a cotter pin 31.

Welded to the upper surface of the guide sleeve 20 is a longitudinallyextending guide plate 32 which may be arcuate in cross section, as seenin FIG. 5, and has longitudinal guide edges 33. The outer end of plate32 is provided with a shallow notch 34 having a configuration to conformto the cross section of handle 29 so as to releasably retain the handletherein.

A guide block 35 is mounted on the latch bolt 22 adjacent handle 29 bymeans of a set screw 36. The guide block 35 has a groove 37 in its uppersurface and receives the longitudinal edges 33 of the guide platetherein.

The latch bolt 22 is slidably mounted for reciprocable movement betweena locked position as illustrated in FIG. 2 and an unlocked position asshown in FIG. 3. When the latch bolt is withdrawn to the unlockedposition, the handle 29 is pivoted upwardly to a radial position withrespect ot the inner drum 12 and seated into the notch 34 on the end ofthe guide plate 32. The latch assembly is thus retained in the unlockedposition.

When it is desired to commence the laundering operation and to lock theinner drum door, it is only necessary for the operator to hit the handle29 downwardly toward the door 13. With very little force, the handlewill become unseated from notch 3 and will be pivoted downwardly to aposition substantially parallel to the door 13 where the handle will beguided along one of the longitudinal edges of the guide plate 32. Whileunder the action of the guide spring, the latch bolt 22 is moved to thelocked position.

The length of the bolt handle 29 is such that when the handle isretained in the unlocked position, it is engageable with either theedges in the door 11 in the outer shell or some other structure locatedon the inner surface of the outer shell. Thus, in the event that theoperator inadvertently commences operation of the laundry machinewithout first latching the door 13 on the inner drum, the rotating innerdrum will cause the handle to contact some part of the outershell andthe handle will be pivoted downwardly. The spring will then move thelatch bolt to the locked position.

Thus, it can be seen that the present invention has disclosed a simpleyet effective structure for a latch bolt assembly which is particularlyadapted for the door of the inner drum of a laundry washing machine. Thelatch bolt assembly has a built-in safety feature in that the operatinghandle extends radially outwardly of the inner drum when the latch isunlocked. When the handle is in this position, it may contact a portionof the outer drum so as automatically to lock the latch as soon as theinner drum begins to rotate. The latch structure comprises a minimum ofcomponents so that maintenance problems are considerably reduced.

It is to be understood that changes in various details of constructionand arrangement of parts may be made without departing from the spiritof the invention.

What is claimed is:

1. A latch bolt for a door of a washing machine drum, comprising abracket having a bore therethrough mounted upon a surface, a guidesleeve attached to said bracket and coaxial with said bore, a latch bolthaving a forward end and outer end slidably mounted in said bracket andguide sleeve, a spring within said guide sleeve urging said latch boltoutwardly of said bracket to the locking position, a handle freelypivotable on the outer end of said latch bolt in a plane perpendicularto the slidable movement of said latch bolt, a longitudinal plate onsaid guide sleeve and extending outwardly therefrom away from saidbracket for guiding the movement of said handle when pivoted to aposition substantially parallel to said surface so that the latch boltis movable to the locking position, and a notch on the outer end of saidlongitudinal plate for releasably receiving said handle when the latchbolt is moved to its unlocked position and the handle is pivoted to aposition substantially perpendicular to said bracket mounting surface,and guiding means on said bolt for slidably engaging said longitudinalplate during the slidable movement of said bolt.

2. A latch bolt as claimed in claim 1, further comprising a guide platemounted on said latch bolt adjacent said handle and slidably mounted onthe longitudinal edges of said longitudinal plate.

3. A latch bolt as claimed in claim 1, further comprising an annularshoulder on said latch bolt, retaining means on the end of said guidesleeve, said spring being between said shoulder and said retaining meansto urge said latch bolt into the locking position.

-4. In a laundry washing machine, the combination of a stationary outercylindrical shell having an access opening therein, a rotary cylindricaldrum rotatably mounted within said outer shell, a door in the wall ofsaid cylindrical drum, a keeper element on said drum adjacent said door,a latch on said door having a reciprocable latch bolt lockinglyengageable with said keeper element, a handle on said latch bolt freelypivotable thereon in a plane perpendicular to the movement of said latchbolt, and means on said latch for releasably retaining said handle in aposition substantially perpendicular to said door when the latch is inthe unlocked position, said handle extending radially outwardly of saiddrum a sufficient distance to engage an edge of said access opening whensaid drum is rotated, whereby the handle will be pivoted out ofengagement with said retaining means to permit the locking of the latch.

5. A laundry washing machine as claimed in claim 4 wherein said latchcomprises a bracket having a bore therethrough mounted upon said door, aguide sleeve attached to said bracket and coaxial with said bore, saidlatch bolt having a forward end and outer end and slidably mounted insaid bracket and guide sleeve, a spring within said guide sleeve urgingsaid latch bolt outwardly of said bracket to the locking position, saidhandle being freely pivotably mounted on the outer end of said latchbolt, and means on said guide sleeve for guiding the movement of saidhandle when pivoted to a position substantially parallel to said door sothat the latch bolt is movable to the locking position.

References Cited UNITED STATES PATENTS 2,438,597 3/1948 Batina 292- X2,490,707 12/1949 Piltz 292-173 FOREIGN PATENTS 344,249 3/ 1931 GreatBritain. 570,762 7/1945 Great Britain.

RICHARD E. MOORE, Primary Examiner O U.S. Cl. X.R. 68139, 143

